Skip desktop/MIME cache refresh for console installers, where no desktop integration files are installed.
Guard update-mime-database and update-desktop-database calls so minimal systems without desktop-file-utils do not print post-install errors.
Apply the same best-effort cache refresh behavior to FreeBSD generic scripts for parity.
Also fix the FreeBSD uninstall script to remove the per-resolution PNG icons from /usr/local/share/icons, matching where they are installed.
This patch moves away from gnome-terminal -e options which is deprecated
and subject to possibly be removed in the future. The -- option is nearly
equivalent in behaviour. Also ensures that uninstallation script has correct
privileges, adds window title to xmessage and ensures correct files are
used during installation.
The x11 aliases such as --title are only available in the Qt application
if the XDG_SESSION_TYPE is x11. Instead of using an alias, we can use
--qwindowtitle directly.